Expansion corner for plaster



May 12, 1925.

A. FISCHER EXPANSION CORNER FOR PLASI'ER Filed July 5, 1924 1 I a m m M vm m M .2, B A fim 2 m 1 w m a 7 d \1 V lwwr a \fl WW 1 5 J w w m w. 7 f 1 8 m 0 A M. 4 A

itself to form a rib 13,, for a purpose Patented May 12, 1925.

UNITED STATES ANTHONY rIscHEn, or INDIANAPOLIS, INDIANA.

EXPANSION oonNnn non EASTER.

Application filed July 5,

To all whom it may concern.

Be it known that I, ANTHONY FISCHER, a

citizen of the United States, residing at Indianapolis, in the county ofMarion and State of Indiana, have invented a new and useful Expansion Corner for Plaster, of which the following is a specification.

In many modern buildings diiii'culty is being experienced at inner corners of rooms, more especially vertical inner corners, because of unsightly and irregular cracking of the plaster due to expansions and contractions of the frame.

The object of my present invention is to provide a construction, for assembly in and along such inner corners, by means of which unsightliness of such cracking may be obviated.

The accompanying drawings illustrate my invention.

Fig. 1 is an end elevation of one form of my improved corner assembly.

Fig. 2 is a perspective of a short section of the construction shown in Fig. 1;.

Fig. 3 is an end elevation of another form embodying my invention;

F at is an end elevation of another modified form.

In the drawings A indicates a bent metal strip which, for convenience, I shall call an end strip, and B indicates a corner strip, two strips A and one strip B being used to make up what may be conveniently called my corner unit.

Each strip A comprises an edge arm 10, an edge arm. 11 which is substantially parallel to arm 10, and an intermediate arm 12, most conveniently lying at right angles to and connecting the two arms 10 and 11. It is also preferable that the sheet, at the junction of arms 11 and 12, be doubled upon which will appear.

Each cornerstrip comprises an intermediate corner-forming portion 15 of any desired form, the sheet, at each end of the portion 15 being bent backto form arms 16, substantially at right angles to each other, thence doubled back at 17 and arms 18 laid alongside of arms 16 a distance therefrom equal to the thickness of arms 11, thus forming channels 19 in which said arms 11 may be projected with a reasonably tightsliding tit. If desired, although not necessary, the edges of the sheet-forming element B may be turned outwardly, at the 1924. Serial No. 724,196.

extremity of arms'18,to form edgearms 2O lying substantially at right angles to each other and tothe arms 18 to which they are connected. The bend line 21, between middle portion 15 and the flanking arms 16 i is preferably sharply formed and has a transverse dimension substantially equal to the height of rib 13, the arrangement being such that said rib 13 will fit nicely against the bend line 21.

Strip B should be formed of imperforate material so that the middle portion 15 will present an imperforate face in the finished job. Strips A however shouldbe formed of perforate material, at least as to arms 10 and 12 so that the plastering 25, indicated in dotted lines in Fig. 1, will properly adhere thereto, but the material of strips A should preferably be of such character that the ribs 18 will present a smooth surface.

My improved corner pieces will be formed in suitable lengths and in use will be assembled, two strips A and an intermediate strip B nested therewith, with ribs 13 closely abutted against fold lines 21, and the strips A nailed or otherwise secured to the frame work of the building. The plastering is then placed and adheres to the strips A. In case of expansions and contractions of the building frame tending to move the strip A toward strip B there will be suificient give in strips B to permit such movement without damage to the plaster, whereas in those expansions or contractions of the building frame tending to draw the plasteraway from the corners, strips A will move relative to the intermediate strip B, arms 11 sliding in channels 19. Such movements will of course draw ribs 13 away from fold lines 21 but the condition thus established plaster and the other being formed to bridge the gap between the first two mentioned strips, said three elements having interdigitated portions in series.

2. A plastering corner unit comprising two end strips and an intermediate corner strip, each end strip comprising two substantially parallel edge arms and an intermediat efconnecting arm and the cornerpiece comprising a strip forming at its middle to bridge between the adjacent edge strips and at its edges bent to form pockets for the reception of an edge arm of an end strip.

3. A plastering corner unit comprising two end strips and an intermediate corner strip, each end strip comprising two substantially parallel edge arms and an intermediate conneq s a m d v l p nt rib projecting beyond the adjacent edge arm and the corner piece comprising a i'strip forming at its middle a bridge between the adjacent edge strips and at its edges bent to "form pockets for the reception of an edge arm of an end strip.

In witness whereof, I, ANTHONY FISCHER, have hereunto set my hand at Indianapolis, Indiana, one thousand nine hundred and twenty-four.

l-meow mouse. 

